Seam reenforcement



Patented; June 20, 1933 raise WILLIAM. WALLACE ROWE, 0F CINCINNATI, OHIO, ASSIGNOR TO THE PAPER SERVICE COMPANY, OF LOG 1 AND, OHIO, A CORPORATION OF OHIO SEAN REENFORCEMENT Application filed November 19, 1928. Serial No. 320,289.

My inventionprovides improvements in seam reenforeements in -crimped or creped fabrics, particularly creped papers. Articles, such as bags, bag liners, barrel liners, aprons, etc., are made of creped papers by joining operations involving the formation of seams. The need for seam reenforcements for the lines of stitching-is apparent and has been recognized.

Hitherto such reenforcements have com prised strips pasted on to the paper webs.

Plain gummed tape or the equivalent has been used but the result is unsatisfactory because the plain reenforcement robs the seam of that elasticity which it is"a prime function of the creped fabric to provide. Strips of creped fabric have also been cemented to the main creped web. Reenforced ment of its subsequent effectiveness.

seam areas formed in this'manner retain some elasticity. It should be noted, however, that any stretching tends to separate and d-is-' rupt the plies; and once the potential stretchability has been realized by an actual stretching, the loosening or detachment of the strip from the body robs the reenforlcle- T is is because, while the stretchability is resident in the crinkles, the two plies of fabric do not stretch together, but each in accordance with its individual crinkling.

'Failure at sewn seams is generally the result of two causes: The paper, weakened by the line of needle perforationsmay tear under strain, or the thread passing through the needle holes may tend to cut the paper. Usually the two causes reenforce each other. But it will be clear that-an extra layer of paper in the seam will have a different result if it is in adhesive contact at all points with the main fabric than if it is not. If such an extra layer is not attached, or is insecurely attached, it may tend to protect an underlying layer from the cutting action of thread; but it will not render the main fabric less liable to tear along the line of It is my further object to provide a meth-- od of forming reenforcements during the creping of the body sheet so that no separate and subsequent operation is necessary for the purpose.

I It is my further object to effect, in practicing said method, a betterment of the edge conditions during creping.

These'and other objects which will be apparent to one skilled in the art upon reading these specifications, I accomplish by that certain process and arrangement of parts of which I shall now describe preferred embodi1nents,reference being made to the drawing forming a part hereof.

In the drawing:

- Figure 1.shows an uncreped sheet and reenforcing strip in position for attachment and simultaneous crepingu Figure 2 is an elevation of a reenforced seam.

Figure 3 is a perspective view of a structure comprising two members, each with a reenforced seam, sewn together as in the formation of a bag, barrel liner, or the like.

Figure'4 shows a sheet of duplex crepe with an'interleaved reenforcement at either without substantial disturbance of the attachment between them. When thus creped, the corrugations are conjoint and the body fabric and the seam reenforcement may stretch together and contract together without any substantial tendency to separate. Thus as in Figure 1, I take a body sheet 1 and a reenforcement 2 and I superimpose them and cement them together before the creping process. This may be done either before the material reaches the creping roll or upon the creping roll but before the material reaches the doctor. The body sheet 1 and the reenforcement 2 may be, of course, of any material suitable for creping and they may be of the same or different materials. It is also to be noted that in one aspect of my invention, the reenforcement 2, while it should be flexible enough to be crinkled, need not be of such character that the crinkling will remain therein, i. e., that it could be permanently creped, since the crinkling of the main sheet will preserve the crinkling of the 'reenforcement. Consequently, I could use as my main sheet for example, a heavy web of kraft paper and as my reenforcing strip 2, a thin body of cheese cloth or the like. However, for a purpose which I- shall presently describe, I prefer to have the reenforce ment 2 of any material which will retain a crepe.

Ordinary creping operations will be understood as conducted upon a creping roll to which a wetted web of fabric isled and from which it is removed and crinkled by a doctor blade as is the practice imthe art. Various types of creping operations produce various results and my invention is not restricted to any particular type. For heavy sewn articles such as barrel liners, tire covers, aprons and the like,-I may use the creping process described and claimed in my Patent No. 1,628,- 515, in which the material is not saturated with water or treated with a water soluble adhesive, but on the contrary is creped with a bituminous adhesive in the absence of water. In any case, the sheet 1 may, as an example, be of heavy kraft caused to adhere to the crepmg roll, and the reenforcing strip 2 may be a strip of kraft or other material cemented to it or it may be a strip or ordinary gum tape which has been moistened before its applicatlon to sheet 1. I prefer to overlap the sheets, causing the rcenforcement to extend, say. one

uarter inch or so beyond the edge of the s eet 1 as is shown at 3. and it is advantageous to have the projecting edge of the reenforccment coated with adhesive on the side to be next the creping roll. This naturally occurs when the reenforcing strip is gummed tape.

In water -creping operations, particularly, the edge ofa sheet is frequentlyrsubject 'to what are known as skips, that is to say. imcrinkled, irregular portions at the edge of the paper caused by its too ready separation. from the roll.. Skips do not occur so readily elsewhere as at an edge of a sheet during creping, because elsewhere, the contiguous portions of the material tend to hold the web against skipping. At and beyond an edge, there is no such holding and the skips are frequently encountered. If a reenforcementwere applied in registry with the edge of the main web, the added stiffness imparted thereby during the creping operation would tend to increase rather than diminish the skipping. If however, I overlap the edge of the reenforcement, say one quarter of an inch or so, and cause it to adhere to the creping roll, the tendency to skip is very greatly diminished. This is of course partly true because instead of having a double thickness of edge having a great tendency to skip, I now have a double thickness of material adjacent the edge but an actual edge of single thickness, Again in the use of gum tape, the added adhesive upon the reenforcement edge will also diminish the tendency to skip. I have discovered that I can very greatly decrease and in some instances eliminate entirely the tendency to skip at the edge of the sheet by superposing a reenforcing which overlaps that edge; and it will be readily understood that this discovery has importance not only in the formation of reenforcements of narrow width for theproduction of seams but in the production .of full reenforced webs by the superposition of complete layers.

It has a further importance in this, that where I desire to produce an article, say a bag, with one edge turned up over the other and sewn in the seam so as to prevent sifting between the fabric plies, I may give to the reenforcement an overlap great enough to accomplish this. Thus, when working with two layers of single thickness paper withedge reenforcement, if I double back the edge before sewing, I decrease the dimension of an article which I can produce from a given width of paper, and I must "sew through eight thicknesses of paper If I allow the reenforcement to overlap say one inch,

and in making the seam I bend back this overlapping portion, the effective width of my paper remains the same, and I sew through but six thicknesses of paper. Figure 6 illustrates a seam of this character in which the overlap of the reenforcement strips 2 on the body fabric layers 1 is an inch or more, the reenforcements being bent back creped overlapping edge. Figure 3 shows two such fabrics with their reenforcements juxtaposed, and a line of stitching 4, fastenzteiaaoa ing them together, the reenforcements preventing tearing and cutting at the line of stitching,

The sheet 1 may also be thought of as a duplex fabric in another embodiment of my invention, the reenforcement 2 may be similarly applied and-the material crepedin the ordinary'fashion. In handling duplex materials, however, I may interleave the reenforcement 2 between the duplex plies as can readily be done during the pasting operation, so that I obtain a final product as 18.

shown in Figure 4. Here again the reenforcement is caused to overlap the edges on the main duplex sheet as shown at 5 for the same purpose. plex sheet of regular width, I will desire to provide several longitudinal reenforcement portions for the formation of several seam reenforcements,as for example, in the manufacture of barrel liners, where the length of the liner is half of the width of the sheet or less. I can dothis as is shown in Figure 5 by providing for the insertion of reenforcement strips 6, 7, 8, etc. between the bottom sheet-9 and the top sheet 10, during the duplexing operation, the strips being longitudinally positioned at the desired lines of reenforcement. A series of longitudinal reenforcements may also, of course, be applied to a duplex or single sheet on the outside. Ihe sheet thus formed will be slit apart, and if the reenforcing strip be wide enough it may be slit midway forming two reenforced portions. The slittingmay be done either before or after the creping and with a creping process involving the use of bitumen as an adhesive, which process is characterized by a practical absence of skips, either method may be followed depending upon convenience. In a water creping operation instances may arise when to slit before creping is to invite skips whereas to slit afterwards will involve no diihculty. When a lean-- forcement is slit'midway, of course, two double-thickness edges are produced, and there is no overlapping of'the reenforcement onto the roll such as I preferably employ when ,7 water creping.

I find that while a reenforcement merely pasted. on the outside of a duplex sheet and overlapping the edges will tend to prevent skips in the same fashion that an overlapping reenforcement upon a single ply body fabric does, I attain a better result by interleaving the reenforcement. I believe this to be due to the fact that the projecting edge of the reenforcement, to reach the roll, has to bend downonly the thickness of one ply rather than two, so that'its tendency to leave the roll is much less. Transverse reenforcing strips may be applied'as an addition to the steps illustrated in Figures 1 and 5 if 'desired. They will fall preferably on the outside of single ply fabrics, i. e., the side Frequently in making a duwhich is not against the creping roll, or within the body of duplex fabrics. creping processes the bitumen coating will usually serve to cement in place intermediate reenforcements, and since the skipping difficulty is not resident in these processes, a

convenient operationin joining two strips of fabric with a seam reenforcement alongone edge, is to associate a reenforcement strip with the body fabric intermediate its edges while the bitumen is still tacky and crepe the composite product, slitting either before or after the actual creping.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is

1. A reenforced seam comprising a layer of creped fabric with an edge reenforcement strip adhesively joined theretoand creped therewith, a second layer of creped fabric with a similar edge reenforcement, said layers superposed so that said reenforcements In bitumeni coincide, and a line of stitching joining said 1 of creped fabric with a seam reenforcement strip adhesively joined thereto and conjointly creped therewith, a second layer of fabric with a similar seam re'enforcement, said layerssuperposed so that said reenforcements coincide as to position, a line of stitching joining'said layers and said reenforcements, and portions of said material turned back over the seam thus formed and caught by said stitching.

42. A reenforced creped fabric comprising a body sheet and a superposed reenforcing strip joined'by adhesive thereto over a proposed lineof seam and the corrugations of the-creping of said sheet and strip being conjoint whereby-they may be stretched together without separation, the lines of corrugations extending transversely of said strip, and wherebyv said fabric may be stitched with said strip forming a reenforcement for said stitching.

5. A reenforced seamed construction comprising a layer ofcreped fabric with a seam to and conjointly creped therewith, a second layer of material, and aline of stitching j oining said layers and passing through said reenforcement strip. 1

reenforcement' strip adhesively joined there- 6. A process of forming reenforced crep'ed structures which comprises providing a web of crepable material, running onto said web longitudinally atleast one strip of crepable material and adhesively securing said strip to said web, afterward creping-said web and said strip conjointly by forming therein creping crinkles essentially transverse to said strip.

7. A process of forming reenforced creped structures which comprises providing a web of crepable material, running onto said web longitudinally a plurality of relatively narrow strips of crepable material and adhesive- 1y securing said strips to said webin interspaced parallel relationship, afterward creping said web and said strips conjointly by forming therein crinkles essentially transverse to said strips, and cutting said composite structure apart into blanks for forming articles in such a way that said strips form reenforcements for said webover lines of proposed seams in said articles.

' WILLIAM WALLACE RQWE. 

